Dual Battery Wiring - ContinuousWave Dual Battery/Dual Engine "New" Schematic NOTE: The battery positive leads are shown in red. The negative leads are shown in green for clarity; code suggests the use of yellow wire. All wiring is AWG-2 unless indicated. The single switch is an OFF-1-BOTH-2 switch. JWH. How to Install a Marine Dual Battery Setup for Your Boat In order for the dual-battery system to operate properly, you need a crossover cable between the negative terminals of the two batteries. Also, connect the negative cable lug from the engine/ground and the negative accessory wire to either of the negative battery posts, Beginners Guide With Diagrams - New Wire Marine A Double Pole ON/OFF/COMBINE battery switch (like this one) is a great choice for a single engine, two battery boat wiring system. I allows your house and start battery to Dual Battery / Dual Engine - Moderated Discussion Areas I don't see where single battery, dual engine is going to blow things. I'd look elsewhere for the source of that problem. A short? Chuck: jimh: and in the process I "invented" a new wiring arrangement for use with dual engines and dual batteries. I have added a schematic diagram to the REFERENCE article Perko Dual Battery Switch Wiring Diagram - Wiring Diagram Description: Installed Perko Switch With Single Engine/two Battery(Cranking in Perko Dual Battery Switch Wiring Diagram, image size 370 X 466 px, and to view image details please click the image. Here is a picture gallery about perko dual battery switch wiring diagram complete with the description of the image, please find the image you need. Boat-Project - Dual Battery Setups. It is not satisfactory to run a single ground wire to one battery and tap to the other battery. While 33CFR183 is applicable for dual engines, it is common industry practice - even with a single engine - to ground batteries at a common ground at the engine.